Ropeless elevator systems, also referred to as “self-propelled elevator systems,” are useful in certain applications (e.g., high-rise buildings) where the mass of the ropes for a roped system is prohibitive and there is a desire for multiple elevator cars to travel in a single lane of a hoistway. There exist ropeless elevator systems in which a first lane is designated for upward-traveling cars and a second lane is designated for downward-traveling cars. A transfer station at each end of the hoistway is used to move cars horizontally between the first and second lanes.
In these elevator systems, batteries or power rails, for example, power brakes to lift and hold the respective cars. Toward this end, the brakes are generally located on the respective movable cars, and control systems and drives are stationary and located in the hoistway. Operation of and communication between the brakes and corresponding drives are configured to be closely coordinated with each other.